Comparison of photoaffinity labeling of P2-purinergic receptors of isolated guinea-pig vas deferens by arylazido aminopropionyl ATP and by arylazido aminobutyryl ATP.
O'Donnell-JP; Hogaboom-GK; Fedan-JS
Eur J Pharmacol 1983 Jan; 86(3-4):435-440
The abilities of two chemically related arylazido photoaffinity analogs of ATP to antagonize contractile responses of the isolated guinea-pig vas deferens to ATP were compared. The two analogues were arylazido-aminopropionyl-ATP (ANAPP3) and arylazido- aminobutyryl-ATP (ANABP3). ANAPP3 caused a contractile response of the guinea-pig vas deferens when initially added to the bath, and no irreversible antagonism of ATP induced responses occurred if the compound was not photolyzed. The ANAPP3 concentration/response curve resembled that for ATP in that it was biphasic. Compared to ATP, the changes in the morphology of responses to low concentrations of ANAPP3 and ANABP3 were similar to those reported for a number of adenine nucleotides with phosphate chain modification which would be expected to render the compounds as lesser substrates for ectophosphohydrolase enzymes. Both ANABP3 and ANAPP3 appeared to have similar time courses for photoconversion. ANABP3 appeared to be a more potent antagonist than ANAPP3, under rigorously controlled conditions, in antagonizing ATP induced responses, but neither compound affected the maximum response to ATP.
NIOSH-Author; Laboratory-animals; Enzyme-activity; Nucleotides; Pharmacology; Drugs; Purines; In-vitro-studies
European Journal of Pharmacology